What resources are available for PHP developers to learn about string manipulation functions?

PHP developers can learn about string manipulation functions by referring to the official PHP documentation, online tutorials, and forums dedicated to PHP programming. These resources provide detailed explanations, examples, and best practices for using string manipulation functions in PHP.

// Example of using string manipulation functions in PHP
$string = "Hello, world!";
$uppercaseString = strtoupper($string);
$reversedString = strrev($string);

echo $uppercaseString; // Output: HELLO, WORLD!
echo $reversedString; // Output: !dlrow ,olleH